Contact-making voltmeter.



C. J. HBJDA.

OOHTAOT MAKING VOLT HETBB.

` union-Ion num 001.11, 1910.

2 SHEETS-SHEET 1.

1,101,798, Patented June 30,1914

C. J. HEJDA.

CONTACT MAKING VOLT METER.

nluumlourlorr FILED 00T.11, 1910.

Patented June 30, 1914 E 2 SHEETS-SHEET 2.

En-gw@ l UNITED STATES 4'rAaENT OFFICE. 'f

:cHARLnsf HnJnA,- or CHICAGO, ILLINOIS, AssmNoR v`-To ASSOCIATED ENGINEERS COMPANY, ,or CHICAGO, ILLINOIS.

CONTACT-MAKING voL'rMETER.

To all 1li/0m #may concern: A

Be it known that I, CHARLES J. HEJDA, a citizen ofthe United States, residing at Chicago, in the countyof Cook and State of Illi- 5 noie, have invented a certain new and useful Improvement in Contact-Making Voltmeters,l of which the following is full, clear, concise', and exact description, refer-- elce being had to the accompanying drawings, forming' a part ot' this specilication.

My invention .relaties to re fulating devices and -While not so limited is o particular utilj ity in connection with -What are styled con? act makingr volt meters. These so called 4contact making voltmetersl comprise means operable with changes in pressure -to increase orI decrease the voltageY of supply circuits.

I will style the instrument of this character in connection with which I am describing 2o my invention aontact making/'volt meter throughout" this specification in conformity With present day terminolog Y: These con- `tact making voit metersontrol Aa movable vcontact or conte ts and the movement ot 25 these contacts is ln conformity with changes in voltage of supply circuit Whose pressure it is desired to maintain as nearly constant as is possible. It is found in practice that when the voltage is at or near normal, these contacts oscillate rapidly or vibrate closeto the tixed Contact terminals with Which they are to be connected in operative relation periodically, and thus burn these contacts and render these instrinnents very delicate,

.-,5 requiring moet frefpfuent attention, and Iby reason or this delicacy and burning of the contacts, weld the cont-acts together in such a Way that the instrument is frequently inoperative for the purpose intended.

My invention is designed to obviate this difiiculty, but I wish it understood of course that my invention is not limited in its` application to contact making volt meters, but is capable of a Lgreat variety of uses. To properly describe my invention, however, in connection with its vapplication to a given system wherein its corrective influence is of great utility, I show it in this application as applied to a system of so called contact mako. ingf voit meters and Will describe it in this connect-ion. Generally speaking myA inventi on provides means to overcome the Libra-` tionsy of these' contact points under consid-v eration and to hold them in. eitherposit-ive i Specicationlof Letters Patent. Application led October 11, 1910. Serial No. 586,468.

Patented June 30,1914'.`v

fixed contact or else to insure theirseparation a sutlicient distance toprevent the objectionable clects of' vibratory contact Aand arcing of the current above outlined.

In the form shown herein my invent-ion takes the form of two solenoids' controllingoo a common core, Which core is in association with a movable contact. Y The two solenoid's depend preferably for their current upon such current as is supplied when the Contact points are close together or in vibratory re- 65 lation. My invention as set forth iii this particular embodiment as outlined above andthe particular form Which'it takes under these conditions lwill now be described in detail by reference to theaccompanying drawings, in which: l Figure l is a front'view of the apparat-us of my invention shown in connection With a contact making volt meter; Fig. 2 is a side view thereof, and: Fig. 3 is a diagrammatic 75 circuit arrangement illustrative of'tlle connections of the various devices. The contact making volt meter consists of a winding l havingtwo coils, a series coil and a shunt coil as Will appear later, which aremounted upon a suitable bracket 2 and having a; movable core 3 associated with an adjustably mounted guide 4. A coil of soft Wire such as solder 5 is used to provide more or less Weight for the core as may be necessary. llerminals 6 permit entrance ofthe 4current through the series coil of the Winding l. The core 3 is attached to a stem 7, which stem is pivotally secured to a rocking lever 8, which rocking lever is pivoted at 9. A contact post 10 and a spiral connecting; wirey 1l furnish electrical connection to the rocking lever and the bracket l2 supports the rocking lever. It Will thus bescen that the movement of the core 3 in response to its 95 attraction, on account of the magnetic intluence of the winding l, causes a rocking of the rocking bar 8 and this rocking effect serves to establish electrical Contact relations between a contact terminal '13a provided upon the left hand extremity of the lever 8 4and two stationary Contact posts lli and 15. TheV contact element 13`is4 held in thelevcr by means of the screw 1G as shown. The Icontact-elements 14 and 15`are held in the binding posts 17 and 18 respectively andaread-r instable shown toward and away, from. the movablecontact' elenientl. New, when the lever 8 is rocked from its norma-l position as shown in the illustration of Fig. 1, it

may cause engagement bctweerrthe Contact ing 1 is connected is raised or lowered. It-

will of course be apparent that when the voltage of the supp y circuit is of a value which is approximately a sli ht deviation from the voltage, which woul either make or break contact between the element 13 and the ele-ments 14 and 15 respectively, that the movable element. remains close to either. one or the"ther ofI these elements and slight changes of .voltage up or down willcause vibration of thelever 8 with vperiodically touching of one or the other of the contacts k14 or 15, thereby producingl anarc and consequent welding xtogether of the contacts. This is a serious defect to the elimination of which my invention is directed'.

In accordance with myinvention I provide two coils 19 and 20 which act, upon a vcommon core 21, which common core is of course shorter.v than the distance between the top of the `coil 19 and the bottom of the coi-l2() so .that an lencrgization of either coil willdraw the core 2 1 up or down under the controlling influence ofan adjustable spring 22. The core 21 at its lower extremity as stated yis secured', to a spring 22- and ,at its upper extremity carries a Vrod23 which is pivotally secured to thc lett hand extremity of the lever 8. 4lt mayhe stated right here that the contact elements 14 and 15 are mounted on liexible springs 24 and 25 respectively, and the rocking lever 8 has a spindle 9 through the agency of which it is rotatably mounted. j.

,ln the of eration of contact vmakin volt meters, the arrangement is such that sould the element instance, a suitable motorl orother device is set in operation yto raise the voltage `and should elements 13 and 15 make contact the same devices are set in operation to lower the'voltage. Now when the elements lland 1'4 are in vibratory contact, it will be ap-4 parent thatl the motor devicesarc subject to frequent and severe shocks due to sudden starting and stopping which not only tends to burn them out-.and render 4'the circuit which they are tocontrcl unstahle in voltage, but also tends toburn these contacts 13,114 or 15 together, thus rendering the entire device ipellcctive.

'lhe circuit arrangement' of my corrective device is suf-,h that the circuit through the coil lflis serially arranged with contact clemcuis lf3 and 14 and thc circuit. through the coil 20 is"scrially arranged with respect to contact elements 18 and 15. 'lhus should elements'lt and lft` be in vihratory contact, sulicientcurrcnt flows through the coil 19 s 13 and'14vmake contact, for.

4them which permits some current to ilo,

that the coils 19 or 20 become o erative to permanently close thecontLact an the motor devices ma work to affect their change in voltage. his change in. voltage goes on until. the, current in the winding 1 is of proper size to o erate the 4core 3 so as to overpower the e ect of the auxiliary inuence of the coils 19 or 20 and thereby disrupting ythe contact between the elements 18 and 14. It mi ht.,be,stated that in the preferred form o adj'usting this instrument, the arm 8 may be desi ed to be normally horizontal, and it wil keep a horizontal position if the voltage is normal. Now the. auxiliary devices maintain 4the vcontacts in closed relation until the voltage of the sup' ply circuit gets b aek to 'normali and then a positive break is made and the arm 8 assumes its preferably horizontal position'. It will of course be understood that for the current conditions in the Winding 1 to be of such character as to overpower the -auxiliary influence of the ycoils 19 kand 20, said current is such that after the Contact is broken the core 3 is in such va position that the Contact element 13 will be removed a considerable distance away from the elements 14 or 15 with which it was last. in contact, for the reason that the current in the winding 1 must have changed suiciently not only to have separated these conI tacts without the influence of the coils 19 or 20, but in addition must have changed sui'ciently to overpower the action of these auxiliary lcoils, consequently substantially separating these contact making elements. Switch levers 26 and 27 in conjunction with contacts 28 and 29 can be used for compensating purposes.

Circuit arrangements of the devices described will be apparent from Fig. 3, where T show the winding 1 as having a seriespoil B0 and a bridged coil 31, the -series coil receiving its current from a series transformer 32 inserted in the line wire 33 of the circuit 33, 34. The circuit 33,84 is one phase of a three phase system supplied by the three phase generator diagrammatically indicated at 35. The pressure coil 31 recci ves its current from the pressure transformer 36. Resistances 37 and 38 are respectively in series with the coils 19 and 20. 1t will of course he understood that the energization of coil l!) draws the corev 21 upwardly and an enerrization Ao the coil 2() draws the core 21 downwzh y.

Filesystem under consideration has a' presy understood in the art is accomplished preferably by rota-ting change of inductive relation between the coils 40 and 39, and' this vis accomplished ,by the `motor regulating dev `vices referred to in the specication, which in this instancemay be a three phase motor, herein illustrated by a three phase armature winding el, it being understood that the amount of inductive relation between the coils 39 and 40 kdepcndsiipon the position l of the movable'elenient of the motor 4l.

` At 'the central station'Where'` the devices above 'described are usedfthere is usually provided an kauxiliary source of three phase current 4:2, 43 andl which is vused to operate these devices. The motor 4l isoperated from this source and one oi` its terminals is permanently 'connected to the three phase conductor 4t2 by means of the conductor 45. The other terminals of'v the motor connect to Contact terminals 46 and {17 to which eurrent is supplied by theswitch elements d3',

49, 50 and 5l. The elementsllS, 49, 50 and 5l are what are technically'termed limit .switches controlled by the rotating element of the motor to prevent burning ont of the motor When it has moved to its limit in one direction. The current to the motor is reversed and its operation controlled by the relays 52 and F3 Which are serially included withthe contact elements 13 and l5 respectively and through the agency ofthe rocking lever 8 between the three phase terminals Llll and 43.

When the elements 13 and 14 are in contact rela 52 o crates throu Oh the affe'nc of a :a n

its associated contact elements to rotate the motor devices 4l in one direction1 and when relay 53 operates the connection is reversed and the motor rotates in the contrary direc tion. 4

lt will be seen from the illustration that the coils l?) and 2() of my improved corrective device are serially associated in circuit with thc elements 13 and ll and l5 respcc tively and resistanccs 37 and 38 respectively between the terminal /l/bthrough the agency of the conductor 54l and terminal 43 through the agency ot' the c onductor 55 so that these coils also receive their current from this three phase source. It will be apparent of course that the relays 52 and 53 serve merely as reversing switch operating devices'. It Will be apparent that the coils 19 and 20 serve to either positivelylreep the elements 13 and lll in positive engagement or else to insure their separation a sul'licient distance to prevent arcing or Vibration, or fluttering Contact. As before stated, I do not mean to imply by 'the above detailed description that my invention is limited in its correctin eectsto use in' a system such as describa?, but in order'to thoroughlydescribe'itsopeia tion and lits eliect, I have includedr in this description an operative system.

Having however thus described one for which my invention-may take and one form of itsmany applications, what I claim as neu7 and desire to secure by Letters Patent is:

l. In combination, a pairof stationary contact members, a floating contactmo'vable from a position in which 1t engages one of gages the other of saidmembers, a pivot-.

ally mountedv bar on which said contact is'.

2. ln'A combinatiomUa-"pair oflstationary".

contact members, a floating contact movable from a, position in Whichiit engages' oneof'y said membersto 'a position'in which it engages theother of said members, a pivotally mounted bar on which said contact is Xedly mounted, electromagnetic mans for operating said contact, and electromagnetic means energized and controlled solely by' the 'engagement of the contact with either member for prolonging the period ofsuch en, ;agement.

3. In combination a circuit closing element, a contact element with which it is adapted .for electrical association, electromagnetic means adapted to operate said ele ment to close or open said contact, said electromagnetic means being .susceptible 'of varying energizations, and auxiliary means 'controlled solely by the engagement of saidv elements for governing said element t0 partly neutralize the effect of the first aforesaid electromagnetic means during the portion of a cycle of the operation of said ele ment thereby to insure positive Contact or positive open circuit between said element and its associated contact.

ln combination an electric circuit having power fluctuations, a circuit controlling element, eIcctromagnctic means responsive to fluctuations in saidelectriccircuit to operatc said element, a stationary contact With which said element is adapted for electrical tsociatiomand means controlled solely byv thc engagement of said elements for'acting upon said element to render it unresponsive to the influence ,of said electromagnetic means duringthat portion of the cycle of its Voperation'bctwccn positive closure of the contact through said clement and a position of said element removed a predetermined distance from said contact.

3 sa-idinembers to a positlonnn which it en- .v

5. In combination a ciieuit closing ele` ment comprising a swinging bar and a contackixedly mounted thereon, electromagnetic means operating upon said element ytending to gradually change .its position in accordance lwith changes of energi'zation of said electromagnetic means, a. contact with i' which said element is adapted for periodic engagement l to change circuit conditions,

`and additional electromagnetiemeans gov- ,erning the 'operation of said element and under the control solelyl ofsaid element.

6. In combination a circuit closing element comprising a swinging'bar and a contact iixedly mountedl thereon, electromagnetic means operating upon said yelement conditions, and additional electromagnetic means governing the operation of said ele! ment, and receiving current'serially through v said element and its associated Contact, whose circuit is controlled solely thereby.

7. A device of the character described.

.comprising a circuit closing element, electromagnetlc means to whose iniiuence said element is gradually re onsive, .a stationary circuit terminal adapte for electrical association with said element, and means controlled solely by the engagement of said elements to influence the operation of said e1e ment whereby under the gradual change of influence of said electromagnetic means said element is adapted for positive association with the terminal `or is adapted to be removed therefrom a snicient distance to` prevent injurious influence.

.In witness whereof, I hereunto subscribe Amy name this 30th day/of September A. D.,

191e. CHARLES J. HEJDA.

Witnesses:

MAX W. ZABEL I-IAznL JONES. 

